<P><FONT SIZE=2>> > SCSI is GREAT, and you should set up redundant hot swaps so </FONT>
<BR><FONT SIZE=2>> if you crash,</FONT>
<BR><FONT SIZE=2>> > you insert a new disk, type "boot", and you're back online </FONT>
<BR><FONT SIZE=2>> with a node. I</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> uh, that misses the whole point of raid, which is to survive hard disk</FONT>
<BR><FONT SIZE=2>> failures. "survive" as in "not crash, keep functioning". raid1 or 5</FONT>
<BR><FONT SIZE=2>> built on IDE disks do this *just*fine*.</FONT>
<BR><FONT SIZE=2>> </FONT>
</P>

<P><FONT SIZE=2>Actually, I'm not just thinking of a single disk crash, but total recovery from a previously</FONT>
<BR><FONT SIZE=2>known, stable backup. Hard to beat a five minute restart time.</FONT>
</P>

<P><FONT SIZE=2>RAID is a great way to go if you anticipate no catestrophic failures.</FONT>
<BR><FONT SIZE=2>A complete rebuild, for example in the event your cluster is connected to the</FONT>
<BR><FONT SIZE=2>outside and someone manages to hack it - or if an innocent scientist works too late</FONT>
<BR><FONT SIZE=2>and runs </FONT>
</P>

<P> <FONT SIZE=2>rm -fR </FONT>
</P>

<P><FONT SIZE=2>on the wrong directory, or if your software vendor dials in and screws up.</FONT>
<BR><FONT SIZE=2>At least you get up and running and buy time to deal with the </FONT>
<BR><FONT SIZE=2>major problem later. It's real important in health care because we can't have down times.</FONT>
</P>

<P><FONT SIZE=2>I'll double check the mechanics of the Perl VM. That I know of, Perl scripts</FONT>
<BR><FONT SIZE=2>are not usually compiled to an object file then linked. </FONT>
<BR><FONT SIZE=2>Not that it's not fast, but with interpretation, there's always overhead.</FONT>
</P>

<P><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> you can also imbed a perl VM in your webserver (mod_perl in apache).</FONT>
</P>